Various types of sterile packing and stents are used in the medical and surgical fields for keeping tissues apart or preventing adhesion. Such uses include, but are not limited to, nasal packing and sinus stents, packing for inner ear surgery, tympanoplasty, exostosis, orbital decompression, as well as various orifice restenosis prevention uses. Personal uses such as tampons, bandaging and the like also involved sterile packing materials.
Such packing and stents have been made from gauzes, microfibers, nonfibrous expandable packing, such as tampons, and the like. Resorbable packing and stent devices have also been developed. Such packing materials have typically included hyaluronic acid (HA), or salts of hyaluronic acids, which are naturally occurring mucopolysaccharides found in various body fluids and connective tissues. Thus, HA is biocompatible. It has been adapted for use as a surgical aid to prevent tissue contact and adhesion formation. Crosslinking has created somewhat insoluble HA materials. Further, other biocompatible materials such as polysaccharides, especially methylcellulosic materials have been combined with the hyaluronic acid to produce packing materials which are resorbable but are also insoluble and have a longer in-vivo residence time before they dissolve into gels and are absorbed by the body tissues. These materials also have increased fluid absorption capabilities.
Collagen is also known for use in the medical field; it is a major protein constituent of connective tissue and is widely used in medical and surgical applications such as sutures, grafts and surgical prostheses. Typical sources include calfskin, bovine Achilles tendons, cattle bones, porcine tissue, human cadaver tissue, and rat tails. Collagen, as an animal protein, is bioresorbable, even when crosslinked to reasonable levels. Collagen is available in a variety of forms including powders and fibrils, and in aqueous solution. Collagen may be provided in insoluble or soluble forms.
It has now been discovered that a flexible bioresorbable foam for packing, post-operative use, and other medical uses may be created having both hemostatic properties and a resorption time of about 14 days (also known as an in-vivo residence time). The foam is formed from carboxymethylcellulose (CMC).